PMC

The gathering evaluation experiments. (a) The PDMS gathering tool gathers the diluted ink in the reservoir. (b) The PMMA gathering tool gathers the diluted ink in the reservoir.

Empirical distribution of gathering sizes by setting (home, work/school, other and total) during UK lockdown in March of 2020 are shown in color as measured in the CoMIX study. For comparison, the corresponding distributions as measured pre-pandemic in the original BBC Pandemic study are shown in gray for each setting.

Here we consider three scenarios for how the transmission probability τ varies with gathering size k. For τ decreasing with k, τ = 0.25 for gatherings with less than 10 people, τ = 0.08 for gatherings with 11 to 50 people, and τ = 0.01 for gatherings with more than 51 people. For τ increasing with k, τ = 0.01 for gatherings with less than 10 people, τ = 0.08 for gatherings with 11 to 50 people, and τ = 0.25 for gatherings with more than 51 people. The solid line is the reference case where τ = 0.08 at all sizes.